A recent project - mother of pearl 'Punisher' fret marker inlays for a local guitar maker. They take bloody ages..! (But look alright...)
The smallest end-mill I used was a 0.2mm on the higher markers - thankfully I only broke the one. Very slow feeds - 1.75mm/sec and a 0.75 DOC.
Attachment 17282Attachment 17283Attachment 17281Attachment 17280
https://www.youtube.com/watch?v=0TjtvOn8yWU
Once installed, the pockets in the pearl will be black-epoxy filled and then sanded back flush to the ebony fingerboard. Looking forward to seeing this coming together - glad I'm not sanding that ebony board, though... For reference - the pockets in the ebony were cut with .08mm clearance - the markers seem to fit very nicely, although I didn't get to push 'em in all the way...
Wal.